The present invention relates to an image forming apparatus such as an electrophotographic copier, which is connected with an outside memory means by electrical means, electrical wave means or optical means in order to control the operation of an outside memory means and the image forming apparatus; for example, in order to positively count the number of copied sheets.
Recently, image forming apparatus, such as copiers, have been widely used, and their performance and functions have made noteworthy progress. These highly functional copiers differ from simple copiers for personal use. In many cases, they are installed in an office and shared by several sections. In this case, expenses may need to be paid by each section according to the number of copied sheets. Therefore, the following means has been adopted: a plurality of portable memory cards (portable memory means) in which the code number of each member of personnel and that of each section are stored, are prepared as an outer memory means; and when a copy operation is performed, this memory card is set to the copy apparatus so that the number of copy sheets can be controlled. For example, this technique is disclosed in the official gazettes of Japanese Patent Application Open to Public Inspection Nos. 165664/1985, 277976/1986, 96958/1987, 96966/1987, and 105964/1989.
In this case, the memory card which is a functional outer memory means is composed in such a manner that: an ID number is registered in the memory card as a card ID number; in the image forming apparatus, a card ID number is stored which is available for the apparatus; when the card ID number stored in the memory card coincides with that registered in the image forming apparatus, image formation can be performed; every time when image formation is performed, the number of image formation is stored in the memory card in order to control the number of copy sheets; and when the card ID number stored in the memory card does not coincide with that registered in the image forming apparatus, image formation can not be performed and the memory card is made invalid.
When the memory card is used in the manner described above, there is a possibility that the following problem occurs. For example, when everybody keeps this memory card and utilizes various copiers, some copiers will not work, depending on the card ID number stored in the memory card.